Low velocity boron micro-pellet injector for edge and core impurity transport measurements
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)
A simple low velocity boron micro-pellet injector has been under development for Current Drive Experiment Upgrade (CDX-U) spherical torus edge and core impurity transport measurements, and wall conditioning. The injector consists of 16 barrels on a rotatable turret. Each barrel can be loaded with boron powder particles of diameters ranging from 1 to 40 {mu}m diameter in amounts ranging from less than 0.25 mg to more than 2 mg. A selected barrel is manually rotated into firing position using a vacuum precision rotary/linear motion feedthrough. A piezoelectric valve gas feed system triggered by CDX-U discharge timing is used to control H{sub 2} or D{sub 2} propellant gas at a cylinder pressure of 5.8{times}10{sup {minus}3thinsp} Pa (40 psi) or less. The injector barrel-to-CDX-U plasma edge distance is 0.47 m. Initial low mass injections of neutral boron beams were performed into CDX-U plasmas at a velocity of 23 m/s. Measurements were obtained with a filtered gated charge coupled device TV camera, bolometry, visible spectroscopy, and ultrasoft x-ray diagnostics. This work is in support of the present CDX-U research program and possible applications on National Spherical Torus Experiment. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 295624
- Report Number(s):
- CONF-980605-; ISSN 0034-6748; TRN: 99:001810
- Journal Information:
- Review of Scientific Instruments, Vol. 70, Issue 1; Conference: 12. topical conference on high-temperature plasma diagnostics, Princeton, NJ (United States), 7-11 Jun 1998; Other Information: PBD: Jan 1999
- Country of Publication:
- United States
- Language:
- English
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